KR101597702B1 - Control method of the three-wheel electric vehicle - Google Patents

Abstract

A control method of a three-wheel electric vehicle according to the present invention is a three-wheel electric vehicle control method including a left front wheel and a right front wheel that are skid-steered, and a rear wheel that is steered by an ackermann, And an input step of receiving the degree of depression of the accelerator pedal or the brake pedal. And a speed measuring step of measuring the speed of the automobile. A turning angle of the steering wheel and a degree of depression of the accelerator pedal or the brake pedal to determine the turning center of the automobile and determining the acceleration in proportion to the degree of depression of the accelerator pedal or the brake pedal. And a control step of controlling the left and right front wheel torque and the steering angle of the rear wheel according to the determined turning center and acceleration of the car. When the speed of the vehicle is less than the predetermined speed, the steering ratio of the steering wheel to the steering angle of the rear wheel of the rotational angle of the steering wheel increases in proportion to the speed of the vehicle until reaching the predetermined ratio. The ratio can be fixed at a predetermined ratio.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a three-

The present invention relates to a control method of a three wheel electric vehicle.

Recently, three-wheel electric vehicles have been developed for three-wheel electric vehicles because they have the advantage of being economical compared to four-wheel electric vehicles in operation. Generally, an electric vehicle is an automobile which drives a motor by using power from a battery, and converts the chemical energy in the battery into electric energy to drive the motor. Electric vehicles have not been put to practical use due to problems such as heavy weight of batteries and time taken for recharging. An electric vehicle that is driven by electricity is advantageous in that there is no exhaust gas or environmental pollution, and noise is very small.

A three wheel electric vehicle is significantly different from an existing automobile, and it is impossible to control the movement of the vehicle in a conventional manner. Therefore, it is required to effectively control a three-wheeled electric vehicle using conventional control mechanisms (steering wheel, accelerator pedal, brake pedal) familiar to the driver.

Korean Patent No. 10-0964348 (published on Jun. 17, 2010)

A control method for controlling a three-wheeled electric vehicle using an input method of a general automobile.

It is an object of the present invention to provide a control method for a three-wheel electric vehicle in which a three-wheel electric vehicle can be turned at a larger angle than a general car at low speed.

An object of the present invention is to provide a control method of a three-wheeled electric vehicle in which the turning ratio of the traveling direction of the vehicle in accordance with the rotation of the steering wheel can be varied according to the speed of the vehicle.

A control method of a three-wheel electric vehicle according to the present invention is a three-wheel electric vehicle control method including a left front wheel and a right front wheel that are skid-steered, and a rear wheel that is steered by an ackermann, And an input step of receiving the degree of depression of the accelerator pedal or the brake pedal. And a speed measuring step of measuring the speed of the automobile. A turning angle of the steering wheel and a degree of depression of the accelerator pedal or the brake pedal to determine the turning center of the automobile and determining the acceleration in proportion to the degree of depression of the accelerator pedal or the brake pedal. And a control step of controlling the left and right front wheel torque and the steering angle of the rear wheel according to the determined turning center and acceleration of the car. When the speed of the vehicle is less than the predetermined speed, the steering ratio of the steering wheel to the steering angle of the rear wheel of the rotational angle of the steering wheel increases in proportion to the speed of the vehicle until reaching the predetermined ratio. The ratio can be fixed at a predetermined ratio.

As described above, in the three-wheel electric vehicle according to the present invention, the driver turns the steering wheel in the same manner as the ordinary automobile, and controls the vehicle by depressing the accelerator pedal or the brake pedal. Therefore, the control method of the three-wheel electric vehicle according to the present invention allows the driver to easily operate the three-wheel electric vehicle having a different drive system from that of the general car. Further, since the steering ratio can be made different depending on the speed of the vehicle, the turning of the vehicle can be made different depending on the speed of the vehicle, and the vehicle can be efficiently controlled.

The control method of a three wheel electric vehicle according to the present invention is characterized in that the control step controls the torque of the right front wheel to be greater than the torque of the left front wheel when the turning center of the automobile is on the left front wheel side, It can be controlled to rotate.

Thus, the three-wheeled electric vehicle according to the present invention rotates the torque of the front wheel and the steering angle of the rear wheel according to the turning center of the automobile, so that the three-wheel electric vehicle can be efficiently rotated.

The control method of a three-wheel electric vehicle according to the present invention is characterized in that the control step controls the torque of the left front wheel to be greater than the torque of the right front wheel when the turning center of the automobile is on the right front wheel side, .

Thus, the three-wheeled electric vehicle according to the present invention rotates the torque of the front wheel and the steering angle of the rear wheel according to the turning center of the automobile, so that the three-wheel electric vehicle can be efficiently rotated.

The control method of a three-wheeled electric vehicle according to the present invention is characterized in that the turning center of the automobile includes a steering ratio (steering ratio (steering angle of the steering wheel / steering angle of the rear wheel) to steering angle of the rear wheel of the steering wheel, As shown in FIG.

Thus, in the three-wheeled electric vehicle according to the present invention, the turning center of the automobile is determined by the steering ratio and the rotation angle of the steering wheel, and the acceleration is determined in proportion to the degree of depression of the accelerator pedal or brake pedal. The three-wheeled electric vehicle can be accurately controlled according to the rotation angle of the steering wheel and the degree of depression of the pedal.

In the control method of a three-wheeled electric vehicle according to the present invention, the turning center of the automobile can be determined by a value obtained by dividing the steering angle of the steering wheel by the steering ratio.

Thus, in the three-wheeled electric vehicle according to the present invention, the turning center of the vehicle determines the value obtained by dividing the steering angle of the steering wheel handle, which is the input of the driver, by the steering ratio, so that the three-wheeled electric vehicle can be accurately controlled.

In the control method of a three-wheeled electric vehicle according to the present invention, different torques are applied to the left and right front wheels along the turning center of the vehicle, so that the vehicle can be skid steered.

As described above, since the three-wheeled electric vehicle according to the present invention applies different torques to the left and right front wheels, the front wheels can be steered without directly rotating. Therefore, the three-wheel electric vehicle can be steered by only the drive motor.

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In the control method of a three-wheeled electric vehicle according to the present invention, when the speed of the automobile is less than a predetermined speed and the steering angle of the rear wheel is greater than a predetermined angle, the turning center of the automobile may be located inside the automobile.

Thus, in the three-wheeled electric vehicle according to the present invention, when the speed of the automobile is less than the predetermined speed, the turning center can be located inside the automobile, so that the automobile can be sprung in a narrow alleyway or parking.

In the control method of a three-wheel electric vehicle according to the present invention, the steering wheel is rotatable less than a maximum of 180 degrees in the clockwise and counterclockwise directions, respectively.

As described above, the three-wheeled electric vehicle according to the present invention can limit the maximum rotation angle of the steering wheel to less than 360 degrees, thereby preventing driver confusion that may occur when the steering wheel rotates more than one turn.

According to the present invention, it is possible to provide a control method of controlling a three-wheeled electric vehicle using an input method of a general automobile.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a control method of a three-wheel electric vehicle in which a three-wheel electric vehicle can be turned at a larger angle than a general car at low speed.

According to the present invention, it is an object of the present invention to provide a control method of a three-wheeled electric vehicle in which the turning ratio of the traveling direction of the vehicle with respect to the rotation of the steering wheel can be varied according to the speed of the vehicle.

1 is a view showing a kinematic model of a three-wheel electric vehicle.
2 is a view showing a free body diagram of a three-wheeled electric vehicle.
3 is a graph showing the longitudinal force along the turning radius.
4 is a graph showing the longitudinal force according to the steering angle.
5 is a graph showing the maximum steering angle condition according to the speed.
6 is a graph showing the maximum running radius condition according to the speed.
7 is a graph showing the steering angle limit according to the speed.
8 is a graph showing the ratio of the steering angle to the speed.
9 is a view showing the steering angle limitation with respect to the speed.
FIG. 10A shows the trajectory of the automobile through the first simulation, FIG. 10B shows the turning radius of the automobile, and FIG. 10C is a graph showing the speed change of the automobile.
Fig. 11A shows the trajectory of the automobile through the second simulation, Fig. 11B shows the turning radius of the automobile, and Fig. 11C is a graph showing the speed change of the automobile.
12 is a plan view showing a schematic structure of a driving motor and a steering motor device for a three-wheel electric vehicle according to the present invention.
13 is a side view showing a schematic structure of a drive motor and a steering motor device for a three-wheeled electric vehicle according to the present invention.
14 is a flowchart of a control method of a three-wheeled electric vehicle according to the present invention.
15 is a view for explaining that the vehicle turns when the steering wheel of the three-wheel electric vehicle according to the present invention is turned to the right.
16 is a view showing a turning center of a three-wheeled electric vehicle according to the present invention when it is located inside the automobile.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Hereinafter, the theoretical background of the present invention will be described first.

In the case of a three-wheeled vehicle in which the front wheel is steered by a torque and the rear wheel is steered by the steering angle, only one steer angle for going to the same route in the steady state is determined. Therefore, it is important to determine the input of the car to go through the desired route through proper torque distribution.

1 is a view showing a kinematic model of a three-wheel electric vehicle.

As shown in Fig. 1, the side slip angles at each wheel are minimized, and the distribution strategy can be determined through a kinematic model which is advantageous from the viewpoint of power consumption. The characteristic of the kinematic model is that the center of rotation is determined at the intersection perpendicular to the front wheel and the rear wheel. Therefore, the geometric structure determines the yaw rate and the side slip angle according to the steering angle and current speed. However, since torque distribution can not be obtained with a kinematic model, dynamic modeling can determine the torque that must be applied to the front wheels.

2 is a view showing a free body diagram of a three-wheeled electric vehicle.

As shown in FIG. 2, assuming that the rear wheel has no driving force and thus the longitudinal force becomes zero, there are five forces acting on the three-wheeled automobile as shown in FIG. The equation of motion in the fixed body system at this time is expressed by equations (B-1) to (B-3).

로 둔다. 윗 식에서 앞바퀴의 횡방향 힘을 나타내는

항을 소거하고 우리가 구하려는 종방향 힘에 대한 식을 다시 써보면 다음과 같다. First, it is necessary to define the desired turning radius according to the rear wheel steering angle. The radius of rotation can be defined as the center of rotation of the intersection of vertical lines on two wheels based on the aforementioned kinematic model. The conditions representing the centrifugal force are represented by a quadratic term according to the velocity, assuming that the velocity is small

. In the above equation, the lateral force of the front wheel

Let us rewrite the expression for the longitudinal force that we want to eliminate by removing the term as follows.

As we can see from the above equation, the force we are trying to obtain is expressed as a function of β and F _R and is not determined as a force. Thus, we can determine the desired force using the rotational center condition of the kinematic model mentioned above. The condition is expressed by the formula (B-6).

Tire modeling is required to calculate the force acting on the rear wheels. The tire model we used was a linear tire model, and the formula is (B-7).

The force of the rear wheel can be calculated using the condition (B-7) obtained earlier.

(B-8) using the geometric conditions (B-9) and (B-7) that were originally assumed.

Therefore, the final equation can be obtained as follows.

(B-4) and (B-5) as shown in the graph of the force according to the turning radius and the steering angle.

The figures and conditions used in the figure below are shown in Table 1.

l = 2.3m l _f = 0.766m w = 1.4m I = 297 kgm ²

Table 1: Dimensions of three-wheeled vehicles

3 is a graph showing the longitudinal force along the turning radius. 4 is a graph showing the longitudinal force according to the steering angle.

In FIGS. 3 and 4, when the steering angle is 90 degrees, when the center of gravity is in the inside and the steering angle is 0 degree, the force acting on the straight line is determined by the two forces acting the same .

Speed limit according to radius of rotation

In the preceding dynamic modeling, it is assumed that the lateral force of the wheel can be infinitely operated using a linear tire model. However, this is a physically impossible situation when the wheels are saturated. Therefore, the speed limit can be set in consideration of this. The maximum transverse force that each wheel can produce is less than the centrifugal force applied to each wheel. Equation (B-12) indicates that the sum of the maximum transverse forces of the tire in the cylindrical coordinate system should be greater than the centrifugal force.

However, in actual conditions, even if one wheel is saturated, the dynamic equation can not be satisfied, so stability may not be guaranteed. Therefore, when the wheel is saturated, the maximum force can be compared with the centrifugal force to further narrow the stability region.

In equation (F) _max Represents the maximum lateral force exerted on the rear wheel. The values were obtained using the tire model of the commercial program CARSIM. Using these two conditions, a graph between speed and maximum steering angle is shown.

5 is a graph showing the maximum steering angle condition according to the speed. 6 is a graph showing the maximum running radius condition according to the speed. 7 is a graph showing the steering angle limitation with respect to the speed. 8 is a graph showing the ratio of the steering angle to the speed.

5, when the speed is 0, the steering angle is 90 degrees. As the speed increases, the steering angle converges to zero. If the driver's condition is located on the right side of the graph, it is likely that the wheels are saturated and the driver is not able to follow the desired path. Therefore, in order to prevent such a dangerous situation, the condition of the vehicle should be positioned to the left of the graph, thereby limiting the maximum steering angle according to the speed. FIG. 6 shows the maximum rotation radius according to the speed, and it can be confirmed that all the rotation radii can be rotated when the speed is 0 km / h. Considering that the steering angle of the vehicle is usually 30 to 40 degrees, it is necessary to solve the steering angle limitation at a point of 30 degrees, about 14.5 km / h, so as to have the same steering performance as that of an ordinary automobile. Therefore, it is possible to express the steering angle limiting condition according to the speed as a graph as shown in FIG.

In addition, the maximum steering angle of the rear wheel according to the steering angle of the driver is controlled according to the speed, and the ratio can be set as shown in FIG. The sensitivity of the steering wheel changes according to the speed. When the driving speed is more than 14.5 km / h, which is the limit of the normal driving speed, the speed ratio is 15: 1. Decreases linearly to 1: 1.

Therefore, based on the results obtained so far, a three-wheel vehicle torque distribution control algorithm is proposed as shown in FIG.

9 is a view showing the steering angle limitation with respect to the speed.

First, when the user's excel, brake, and steering steering inputs are input, the steering angle of the rear wheel and the longitudinal force to be applied to the front wheel are determined through equation (B-11). At this time, the maximum steering angle and sensitivity are determined by using the speed sensor attached to the present wheel, and then the user's input steering angle is set not to be larger than the maximum steering angle limit.

Confirmation through Kassim simulation

Based on the results obtained earlier, we have verified it through the Kassim simulation. The following situation compares the CARSIM model when the rear steering angle is steered at 90 degrees and 30 degrees, respectively.

FIG. 10A shows the trajectory of the automobile through the first simulation, FIG. 10B shows the turning radius of the automobile, and FIG. 10C is a graph showing the speed change of the automobile.

Fig. 11A shows the trajectory of the automobile through the second simulation, Fig. 11B shows the turning radius of the automobile, and Fig. 11C is a graph showing the speed change of the automobile.

10A to 11C, the model of the passcam model and the model according to the present invention are almost similar to each other and a desired path can be identified. However, the slope value is different in the velocity graph of each simulation situation. The reason for this is that the dynamic model according to the present invention does not take into consideration the centrifugal force, the frictional force, the air resistance, or the like. Therefore, precise control can be performed when it is possible to consider these forces through more precise sensing.

The theoretical background of the present invention has been described above. Hereinafter, a control method of a three-wheeled electric vehicle according to an embodiment of the present invention will be described.

12 is a plan view showing a schematic structure of a driving motor and a steering motor device for a three-wheel electric vehicle according to the present invention.

12, the three-wheeled electric vehicle includes a left front wheel 100, a right front wheel 110, a rear wheel 120, a first driving motor 200, a second driving motor 210, a steering motor 220, And may include a steering wheel 400, a first driving shaft 300, a second driving shaft 310, a steering shaft 320, an accelerator pedal 410, a brake pedal 420, and a computing device 500. In the specification, the three wheel electric vehicle having two front wheels and one rear wheel is described as an example, but the present invention is not limited thereto. Specifically, a three wheel electric vehicle according to an embodiment of the present invention may be a three wheel electric vehicle including one front wheel and a rear wheel including a left rear wheel and a right rear wheel.

12, the left front wheel 100 is disposed on the front left side of the automobile, the right front wheel 110 can be disposed on the right side of the front side of the automobile, and the rear wheel 120 is disposed on the rear side center position of the automobile do. The first driving motor 200 transmits the driving force to the left front wheel 100 and the second driving motor 210 transmits the driving force to the right front wheel 110. The steering motor 220 transmits the steering force to the rear wheel 120 .

The first driving shaft 300 connects the left front wheel 100 and the first driving motor 200. The first drive shaft 300 transmits the rotational power generated by the first drive motor 200 to the left front wheel 100. The second driving shaft 310 connects the right front wheel 110 to the second driving motor 210. The second drive shaft 310 transmits the rotational power generated by the second drive motor 210 to the right front wheel 110. The steering shaft 320 connects the steering motor 220 and the rear wheel 120. The steering shaft 320 rotates the rear wheels 120 toward the left front wheel 100 or the right front wheel 110 of the vehicle in accordance with the rotation of the steering motor 220.

The steering wheel 400 may be provided at one of the front left side of the automobile and the front right side of the automobile and may be located at the center, and the position thereof is not limited to a specific position. The rear wheel can be rotated by operating the steering wheel 400 manually by the driver. A signal corresponding to the rotation angle of the steering wheel 400 is transmitted to the computing device 500. The computing device 500 controls the first driving motor control signal, the second driving motor control signal, and the steering motor control signal Signal. The generated first drive motor control signal, second drive motor control signal, and steering motor control signal are transmitted to the first drive motor 200, the second drive motor 210, and the steering motor 220, respectively.

For example, when the driver rotates the steering wheel 400 to the left, the turning center of the automobile is located on the left front wheel 100 side. At this time, the computing device 500 controls the rear wheel 120 to rotate toward the right front wheel 110 side. That is, the steering motor control signal for causing the rear wheel 120 to rotate clockwise is generated. Further, the first and second driving motor control signals are generated so that the torque of the right front wheel 110 is greater than the torque of the left front wheel 100. [

 When the driver rotates the steering wheel 400 to the right, the turning center of the automobile is positioned on the right front wheel 110 side. At this time, the computing device 500 controls the rear wheel 120 to rotate toward the left front wheel 100 side. That is, the steering motor control signal for causing the rear wheel 120 to rotate counterclockwise is generated. And generates first and second driving motor control signals so that the torque of the right front wheel 110 is smaller than the torque of the left front wheel 100. [

The first drive motor 200 and the second drive motor 210 may provide skid steering by providing different torques to the left front wheel 100 and the right front wheel 110. [ For example, when the steering wheel 400 is rotated to the left, the torque of the right front wheel 110 may be greater than the torque of the left front wheel 100. [ For example, when the steering wheel 400 is rotated to the right, the torque of the left front wheel 100 may be higher than that of the right front wheel 110. [ Steering motor 220 can provide steering only (Ackermann) by adjusting the angle of rear wheel 120.

13 is a side view of a three wheel electric vehicle according to an embodiment of the present invention. The steering motor 220 provided on the rear wheel can connect the steering shaft 320 of the steering motor 220 to the rear wheel so as to steer the rear wheel 120. [

For example, although the steering motor 220 of the rear wheel is vertically connected to the rear wheel 120, the steering motor 220 of the rear wheel may be diagonally connected to the rear wheel 120, unlike the figure.

Hereinafter, the control method of the three-wheel electric vehicle will be described.

14 is a flowchart showing a control method of a three-wheeled electric vehicle according to an embodiment of the present invention.

14, a method of controlling a three-wheeled electric vehicle according to an embodiment of the present invention includes a step of inputting a rotation angle of the steering wheel 400 and a degree of depression of the accelerator pedal 410 or the brake pedal 420 A determination step S20 of determining the turning center and the acceleration of the automobile according to the rotational angle of the steering wheel 400 and the degree of depression of the accelerator pedal 410 or the brake pedal 420, And a control step S30 for controlling the torques of the left and right front wheels 100 and 110 and the steering angle of the rear wheel 120 according to the acceleration. Here, the turning center of the automobile can be defined as a center point of turning the center of gravity of the automobile, and the automobile rotates based on the turning center. The traveling direction of the vehicle based on the turning center can be defined as an angle between a longitudinal center line of the vehicle and a direction line extending from the center of gravity of the vehicle, and the acceleration of the vehicle can be defined as an acceleration of the center of gravity of the vehicle.

15 is a view for explaining that the vehicle turns when the steering wheel of the three-wheel electric vehicle according to the present invention is turned to the right.

The rear wheel 120 rotates to the left front wheel 100 so that the turning center C of the car is formed on the right side of the vehicle and the torque of the left front wheel 100 is transmitted to the right front wheel 100. [ (110). Therefore, the automobile can rotate to the right with respect to the turning center C. The turning center C of the automobile is determined by the steering ratio of the steering angle of the steering wheel 400 to the steering angle of the rear wheel 120 and the steering ratio of the steering wheel 400 to the steering angle of the rear wheel 120 Is determined by the rotation angle of the steering wheel 400. The acceleration a is determined in proportion to the degree of depression of the accelerator pedal 410 or the brake pedal 420. [ Specifically, the turning center C of the automobile can be determined by a value obtained by dividing the rotational angle of the steering handle 400 by the aforementioned steering ratio. This steering ratio can be determined in consideration of the current speed of the vehicle, the roll stability of the vehicle, the degree of wear of the tire, and the possibility of rollover of the vehicle. It is possible to restrict the position of the turning center by limiting the steering ratio at a predetermined value at the time of high-speed driving of the vehicle, thereby securing the roll stability at the time of vehicle rotation and lowering the possibility of rollover. In addition, the acceleration (a) of the automobile can be selected to a preset value according to the depression depth of the brake pedal 420 of the accelerator pedal 410. Even if the vehicle has the same acceleration, the amount of torque applied to the front wheels 100 and 110 depends on the steering angle. Accordingly, the amount of torque of the front wheels 100 and 110 and the steering angle of the rear wheel 120 are determined according to the acceleration a and the turning center C of the automobile.

 Meanwhile, the control method of the three-wheeled electric vehicle according to the embodiment of the present invention may further include a speed measuring step of measuring the speed of the automobile. Therefore, the three-wheeled electric vehicle according to the embodiment of the present invention may further include a speed sensor for measuring the speed of the automobile.

A control method of a three wheel electric vehicle according to an embodiment of the present invention is a method of controlling a three wheel electric vehicle according to an embodiment of the present invention in which when a user inputs an input through a steering wheel 400 and an accelerator pedal 410 or a brake pedal 420, It can be different.

Specifically, when the measured speed of the automobile is equal to or lower than the predetermined speed, the steering ratio increases in proportion to the speed of the vehicle until the steering ratio reaches the predetermined ratio, and when the speed of the vehicle is equal to or higher than the predetermined speed, . Therefore, when the vehicle moves below a predetermined speed, the rotation angle of the steering wheel 400 corresponds to the traveling direction? At the center of gravity of the vehicle, and the steering ratio increases from 1: 1 in proportion to the speed of the vehicle. In addition, when the vehicle moves at a speed higher than the predetermined speed, the steering ratio of the three-wheel electric vehicle according to the embodiment can be set to be 15: 1 to 20: 1, which is the same as that of a general car. The steering ratio can be fixed by considering the size, weight and maximum speed of the vehicle.

16 is a view showing a turning center of a three-wheeled electric vehicle according to the present invention when it is located inside the automobile.

16, when the speed of the three-wheel electric vehicle is less than the predetermined speed, the turning center C of the vehicle may be located inside the vehicle if the steering angle of the rear wheel 120 is greater than a predetermined angle. In the case of a three-wheeled electric vehicle according to the embodiment of the present invention, the turning center C of the vehicle is located at a position where the vehicle is traveling, Lt; / RTI > Specifically, when the steering angle of the rear wheel 120 is greater than a predetermined angle when the automobile moves below a predetermined speed, the turning center C of the automobile is located inside the automobile. Therefore, it is useful when passing through a narrow alley or parking.

In addition, the steering wheel 400 of the three-wheel electric vehicle according to the embodiment of the present invention is rotatable less than a maximum of 180 degrees in the clockwise and counterclockwise directions, respectively. Since the steering wheel is mechanically connected to a general automobile, the automobile according to the embodiment of the present invention uses the steering-by-wire technology, which is an electronic structure, so that it is not necessary to increase the steering angle of the steering wheel 400. [ Therefore, the maximum rotation angle of the steering wheel 400 can be limited to less than 360 degrees, thereby preventing driver confusion that may occur when the steering wheel 400 rotates more than one turn.

On the other hand, when the vehicle is traveling at a speed lower than the predetermined speed, the three-wheel electric vehicle has the traveling direction beta of the vehicle at a maximum of 90 degrees. At this time, the display inside the automobile may include an omnidirectional camera showing the periphery of the automobile. Specifically, the three-wheeled electric vehicle according to the embodiment may include a camera showing a Bird-eye view. The three-wheeled electric vehicle according to the embodiment can move in all directions below a predetermined speed, so that the driver can safely move the vehicle using a camera that can see all the paths outside the vehicle. Thus, the driver can more easily predict and control the movement of the vehicle.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It can be understood that The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

100: Left front wheel
110: right front wheel
120: Rear wheel
200: first drive motor
210: second drive motor
220: Steering motor
300: first drive shaft
310: second drive shaft
320: Steering axis
400: steering wheel
410: accelerator pedal
420: Brake pedal
500: computing device

Claims (9)

A three-wheel electric vehicle control method including a left front wheel and a right front wheel skid-steered, and a rear wheel steered by an ackermann,
An input step of receiving a rotation angle of the steering wheel, and a degree of depression of the accelerator pedal or the brake pedal;
A speed measuring step of measuring a speed of the automobile;
A determining step of determining the turning center of the automobile according to the rotational angle of the steering wheel and the degree of depression of the accelerator pedal or the brake pedal and determining the acceleration in proportion to the degree of depression of the accelerator pedal or the brake pedal; And
A control step of controlling the torques of the left and right front wheels and the steering angles of the rear wheels according to the determined turning center and acceleration of the vehicle;
Lt; / RTI >
Wherein the steering angle ratio of the steering angle of the steering wheel to the steering angle of the rear wheel increases in proportion to the speed of the vehicle until the steering angle reaches a predetermined ratio,
Wherein the steering ratio is fixed at the predetermined ratio when the speed of the automobile is equal to or greater than the predetermined speed. The method according to claim 1,
Wherein the control step comprises:
When the turning center of the automobile is on the left front wheel side,
Controls the torque of the right front wheel to be greater than the torque of the left front wheel and controls the rear wheel to rotate to the right front wheel side. The method according to claim 1,
Wherein the control step comprises:
When the turning center of the automobile is on the right front wheel side,
Controls the torque of the left front wheel to be larger than the torque of the right front wheel and controls the rear wheel to rotate to the left front wheel side. The method according to claim 1,
Wherein the turning center of the vehicle is determined by a steering ratio of a steering angle of the steering wheel to a steering angle of the rear wheel and a steering angle of the steering wheel,
Three-wheel electric vehicle control method. 5. The method of claim 4,
Wherein the turning center of the automobile is determined by a value obtained by dividing a turning angle of the steering wheel by the steering ratio. The method according to claim 1,
Wherein the right and left front wheels are provided with different torques according to the turning center of the automobile to be skid steered. delete The method according to claim 1,
Wherein the turning center of the automobile is located inside the automobile when the steering angle of the rear wheel is greater than a predetermined angle when the speed of the automobile is less than the predetermined speed. The method according to claim 1,
Wherein the steering wheel is rotatable less than a maximum of 180 degrees in a clockwise and counterclockwise direction, respectively.

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